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We bought this van last month and love it. Recently we've been getting a "parking brake unavailable" error and the car won't start. After a few minutes and retries it will start. Now we are stuck in a parking lot because it won't start at all. Is anyone else having this issue? Is there a trick to get it started? We can't be the only one having this issue right??!
 

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Probably a bad battery based on this thread:
 

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What did you find out? This has been happening to our 2021 and when we brought it in last time, they wouldn’t replace the battery, told us it was the Bluetooth draining the battery and reset something that was supposed to fix it. Well 2 months later and it’s happening again, so I need to know what to fight for when I walk in that dealership!. What worked to fix this problem for you?
 

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2021 Sienna XLE
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There is a problem with the DCM (cellular modem) in the early build Siennas. The problem was related to the modem losing signal and then never reconnecting with the signal. This caused the DCM to keep trying to connect and would run the battery down if the car was parked for a few days. There is a firmware update available for the DCM that fixes the issue. The dealer should be able to install the update using their tool. Not sure what the version numbers are for the update.
 

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thanks so much for your reply! I believe that’s what the dealership did last time we brought it in, and we were good for a couple months. But In the last two weeks, it hasn’t started two different times. My husband just jump starts it and we’re good for a couple days, but we shouldn’t have to be jump starting our brand new van to use it! Will we have to keep bringing it in for software updates? That’s kind of a pain. This is our first time buying a brand new car, and I thought we’d be maintenance free for a couple years, maybe that was just super naive of me to think that. Have you had to bring yours in again to have the software updated? Or was it just a one time thing?
 

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Mine was built with the software update at the end of January. Cars these days with all the electronics and processors may need to have updates occasionally installed.

Batteries do not like to be run down so they are dead. It is possible that the first event negatively affected the battery. I would bring it back to the dealer so that they can diagnose the problem. They should be able to test the battery and find out what might be causing the battery to run down.
 

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2021 XLE
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If this is a problem, I suggest going to the dealer for the firmware update.

If your battery was run down, it may not recover normally. I find the onboard battery charger to be a little weak. The dealer may not be nice about replacing the 12v battery. You can ask them to charge it overnight. That should help. I don’t think it would have been discharged to the point of permanent damage.


A brand new car should be kept in top shape by the dealer. If you are going to keep the car for a long time, I suggest getting a 12v battery maintainer and plugging it in overnight at least once every winter. As well as anytime the car is parked for over a week.
 

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I have the 2021 Toyota Sienna hybrid. I had to have it towed to the dealership last week (from Grocery store) as it would not start. It has about 5,745 miles on it. I had same error message of braking power low, parking brake unavailable, antilock brake malfunction, precollision system malfunction. Once there at Kendall dealership, they could not jump it to get it started and had to have a company tow it in the garage. Turns out they say it's a faulty battery. Ironically, right after mine was brought in, a second Sienna hybrid was towed in and they said for the same reason. They've had it for 10 days now and I still don't have it back! They are waiting for battery bracket on order that they broke! I'm hoping this is not a continuous problem with this vehicle!
 

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If both were new, they likely had a problem with the battery supplier for a group of vehicles built around the same time. The supply chain issues result in more than just delays on delivery, apparently. Seems some suppliers are slipping on quality, too.
 

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2021 Sienna Platinum AWD; 2013 Subaru Outback Limited
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We bought this van last month and love it. Recently we've been getting a "parking brake unavailable" error and the car won't start. After a few minutes and retries it will start. Now we are stuck in a parking lot because it won't start at all. Is anyone else having this issue? Is there a trick to get it started? We can't be the only one having this issue right??!
Same exact thing happened to me tonight in a grocery store parking lot. Everytime I tried to start the van, it would not start and kept giving me this aggravating message “parking brake unavailable”! I didn’t even use the parking brake - argh!!

The only different thing I could think of is that I was in the back seat watching YouTube on the large screen for about 10 mins while the vanwas inaccessory mode (dual start button push without hitting brake). Maybe 10 mins max.

I sat there for a while thinking what was I going to do - since it did not start after 20 tries. I was wishing they kept the key-in-ignition solution, because then i could do something! I tried it once more and it started! How Ridiculous !

I looked at my battery on the dashboard display and it was 1 bar above halfway.

will definitely have this looked at during 10K checkup next month! Frustrating!
 

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Same exact thing happened to me tonight in a grocery store parking lot. Everytime I tried to start the van, it would not start and kept giving me this aggravating message “parking brake unavailable”! I didn’t even use the parking brake - argh!!

The only different thing I could think of is that I was in the back seat watching YouTube on the large screen for about 10 mins while the vanwas inaccessory mode (dual start button push without hitting brake). Maybe 10 mins max.

I sat there for a while thinking what was I going to do - since it did not start after 20 tries. I was wishing they kept the key-in-ignition solution, because then i could do something! I tried it once more and it started! How Ridiculous !

I looked at my battery on the dashboard display and it was 1 bar above halfway.

will definitely have this looked at during 10K checkup next month! Frustrating!
The problem with starting is related to the 12 volt battery being run down enough that it could not properly power the computers that run the car. This could be related to using too much power in accessory mode or it could be a bad battery. The 12 volt battery is smaller than a non-hybrid as the 12 volt battery does not operate a starter like in a non-hybrid. The engine is started by a motor powered by the high voltage traction battery.

The dashboard battery display shows the state of charge of the high voltage traction battery and is unrelated to the state of charge of the 12 volt battery. The traction battery can will typically vary between 3 bars and 8 bars(full). It can be full while the 12 volt battery is dead. The car cannot start without the 12 volt battery.

Have the dealer test the 12 volt battery.
 

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Thank you to the forum, the same message just killed our Venza 2021 hybrid. Everything turned black just one moth after towing to the dealership because of the dead battery. It is under warranty but we expected the same - no problems for sometime. what is wrong with their quality?
 
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